Hydrothermal synthesis, structures and properties of coordination polymers based on μ4-bridging benzene-1,2,4,5-tetracarboxylate:

Design of a Sensitive Fluorescent Zn-Based Metal-Organic Framework Sensor for Cimetidine Monitoring in Biological and Pharmaceutical Samples

A new highly fluorescent zinc-organic framework [Zn₂(btca)(DMSO)₂]_n (Zn-MOF) was prepared via in situ ligand formation by the solvothermal reaction of Zn(NO₃)₂·6H₂O and pyromellitic dianhydride (PMDA) in DMSO solvent. During the solvothermal reaction, PMDA was gradually hydrolyzed to a pyromellitic acid, 1,2,4,5-benzene tetracarboxylic acid (H₄btca), to provide a tetracarboxylic acid as a linker in the reaction medium. Single-crystal X-ray diffraction analysis exhibits a 3D porous structure with open tetragonal channels running along the crystallographic c-axis. The Zn-MOF was explored as an on-mode fluorescent sensor for tracing cimetidine in biological fluids and pharmaceutical samples in the presence of interfering species. The results show a quick response in a short time range. The characteristics of this sensor were investigated by field-emission scanning electron microscopy, dynamic light scattering, energy-dispersive X-ray analysis, powder X-ray diffraction, Fourier transform infrared and UV-vis spectroscopy as well as thermogravimetric, and elemental analyses.

Old materials with new tricks: multifunctional open-framework materials

The literature on open-framework materials has shown numerous examples of porous solids with additional structural, chemical, or physical properties. These materials show promise for applications ranging from sensing, catalysis and separation to multifunctional materials. This critical review provides an up-to-date survey to this new generation of multifunctional open-framework solids. For this, a detailed revision of the different examples so far reported will be presented, classified into five different sections: magnetic, chiral, conducting, optical, and labile open-frameworks for sensing applications. (413 references.)

Highly Stable Chiral Cadmium 1,2,4-Benzenetricarboxylate: Synthesis, Structure, and NLO and Fluorescence Properties

Employing an unsymmetrical 1,2,4-benzenetricarboxylate as a bridging ligand, a new 3-D chiral cadmium coordination polymer [Cd(2)(OH)(1,2,4-BTC)] (1,2,4-BTC = 1,2,4-benzenetricarboxylate) has been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction. This compound crystallizes in the orthorhombic space group P2(1)2(1)2(1), with cell parameters a = 6.900(2) A, b = 7.404(3) A, c = 19.116(5) A, V = 976.5(5) A(3), and Z = 4. Its structure contains 2-D Cd-O-Cd connectivity, which is further linked by the 1,2,4-BTC ligand into a 3-D supramolecular framework. The 1,2,4-BTC ligand shows a novel and unprecedented coordination mode: nine bonds to eight metals with each carboxylate as a tridentate group. The compound exhibits intense photoluminescence at room temperature and shows distinct NLO properties. On the basis of the results of TG/DTA analyses, the structure is thermally stable up to approximately 380 degrees C.